Power-transmission mechanism.



H. E. MARSHALL dz R. ISAKSEN.

POWER TRANSMISSION MECHANISM.

APPLICATION 11.21) 111111: a. 1911.

1,023,262. PatentedApr.16,l9l2.

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H. E. MARSHALL & R. ISAKSBN.

POWER TRANSMISSION MECHANISM.

APPLICATION Hum mm a. 1911.

1 ,023,262. Patented Apr. 16, 1912.

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COLUMBIA PLANDGRAPH :0. WASHINGTON. n, c,

H. E. MARSHALL & R. ISAKSEN.

POWER TRANSMISSION MEGHANISM.

urmourmn FILED JUNE 8. 1911 1,023,262. Patented Apr. 16, 1912.

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Patented Apr. 16, 1912.

APPLIOATIOE FILED JURE8.1911.

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COLUMBIA PLANOGIIAPH can WASHINGTON. [:4 c.

UNITED STATES PATENT oFFIcn.

HERBERT E. MARSHALL AND ROBERT ISAKSEN, CF BROOKLYN, NEW YORK.

POWER-TRANSMISSION MECHANISM.

To all whom it may concern:

Be it known that we, HERBERT E. MAR- SHALL and ROBERT ISAKSEN, citizensof the United States, both residing at the borough of Brooklyn, in thecounty of Kings and State of New York, have invented certain new anduseful Improvements in Power- Transmission Mechanism, of which thefollowing is a specification, reference being had therein to theaccompanying drawings, forming part thereof.

Our invention relates to power transmission mechanism and isparticularly adapted for use in motor vehicles.

One of the objects of our invention is to provide a simple, durable andreliable transmission mechanism, by means of which the relative speedimparted to the driven parts may easily be varied, and by means of whicha considerable number of small changes in relative speeds may beeffected.

Another object of our invention is to provide simple and effective meansfor reversing the direction in which motion is imparted to the drivenparts.

Other objects are economy in construction and maintenance, conveniencein operation, and simplicity and compactness of structure.

Still other objects and advantages of our invention will appear from thefollowing description.

In its preferred embodiment our invention comprehends a frictiontransmission mechanism including two friction elements, each having afriction surface oppositely disposed to that of its complementaryfriction element, and an intermediate friction disk interposed betweenthe two friction elements in peripheral contact therewith and arrangedto he angularly adjusted. The friction surfaces of the friction elementsand the periphery of the disk are provided with teeth extending in thedirection of relative movement of the surfaces, so that the frictiongrip of these surfaces is increased and they are held locked in anyposition of adjustment so long as the teeth are maintained inintcrn'leshed or engaged position.

0111' invention also comprehends various combinations and arrangementsof parts, as will hereinafter more fully appear.

o shall now describe the embodiment of our invention illustrated in theaccompany- Specification of Letters Patent.

Application filed June 8, 1911.

Patented Apr. 16, 1912.

Serial No. 631,999.

ing drawings, and shall thereafter point out our invention in claims.

Figure l is a. plan View of a transmitting mechanism embodying ourinvention. Fig. 2 is a side elevation of the same. Fig. 3 is a verticalsection of the same taken 011 the line 3--3 of Fig. 1 looking toward theleft. Fig. 4 is a similar view taken on the line 4 of Fig. 1. Fig. 5 isa central horizontal sectional detail on an enlarged scale of thetransmission head. Fig. 6 is a detail side elevation of the sector forthe controlling lever. Fig. 7 is a detail side elevation of theadjusting lever for the slidable friction head. Fig. 8 is a detail endelevation of one of the swinging sup-ports for the intermediate conepulleys 1n the reversing mechanism.

In the illustrated embodiment of our invention, showing the adaptationthereof to a motor vehicle, we employ a transmission head including afriction driving head 1 and a complementary cooperating friction drivenhead 2, the former fixed on the engine shaft 3, which we term the driveshaft, and the latter slidably mounted on the squared end of a drivenshaft 4 arranged in alinement with the engine shaft. The slidingmovement of the driven head 2 is limited by a shoulder on the drivenshaft 4 at the end of the squared portion, as shown in Fi 5, and acoiled thrust clutch spring 6, which surrounds the shaft 4, bears at itsrear end against a usual thrust ball bearing 7 interposed bet-ween therear end of the spring and the stationary shaft support 8, and theclutch spring bears at its front end against a neck or boss on thedriven head 2 and tends to force the driven head toward itscomplementary driving head.

The opposing faces of the friction heads 1 and 2 are provided withregistering annular concave friction faces concentric with the axes ofthe friction heads. To transmit rotation from the driving to the drivenhead we employ a plurality of rotary friction transmitting pulleys ordisks 9 (shown as two), arranged to frictionally engage the frictionfaces at their respective peripheries. These transmission disks aremounted for rotation in swinging frames 10 which are pivoted on verticalaxes to permit the disks to be turned angularly to change their arcs ofengagement with the two friction surfaces.

To augment the frictional adhesion or grip between the transmissiondisks and the friction faces, each friction face is provided with aplurality of annular teeth concentrio with the friction faces, and thedisks are provided with circumferential teeth adapted to mesh with thoseof the friction faces. These teeth are tapered or beveled off at theirouter edges so that they will retain,.the same relative shape as theywear off.

The frames 10 (see Fig. 4) are pivoted on vertical axes, each framebeing provided at its bottom with a short trunnion 11 which bears in acarrier or base 12, and at its top with longer trunnions 13, whichlonger trunnions extend up through bearings provided for them inoppositely extending arms of a bracket 14 secured by bolts to the top ofa central upward extension on the base 12. This central upward extensionserves as the front bearing for the driven shaft 4, ball bearings beingprovided, as shown in Fig. 4. To swing the frames 10 on their verticalaxes and thus similarly adjust the angular disposition of thetransmission disks 9, crank arms 15 are fixed on the upper end of thetrunnions 13 and to these crank arms are operatively connectedbell-crank levers 16, which are manually operated through means whichwill be described hereinafter.

It is apparent that the angular disposition of the transmission disks 9cannot be adjusted until after the cooperating members have beenseparated and the teeth no longer mesh, and to thus separate themembers, we provide means operated by the treadle 17 to successivelymove the drive head 2 away from the transmission disks, and thetransmission disks out of mesh with the driving head 1. The treadle 17,through a bell-crank lever, operates a slide-rod 18, which passesloosely through a bore in the base 12 of the tIilllSlIllSSlOll disks,and at its inner end passes through an elongated bore in the free sideof a pivoted adjusting lever 19 for the slid-able driven head 3. Nuts 20on the slide-rod 18. one on each side of the adjusting lever 15;), serveto op eratively connect the slide-rod to the ad justing lever, while theelongated opening in the lever. through which the slide-rod passes.permits the pivotal movenurnt of the lever. The adjusting lever 19 is ofan irregnlar shape and is 'iivotcd on a vertical axis and has abifurcated part opposite its pivoted side which straddles a groove if)in the neck of the driven head 2. being attached thereto by set-screws.The base 12 is slidably mounted on lWtl gnidc rods 21. and the sliderod1H carries a nut in front of the base 12 and slightly removed from thebasc \vbcn the treadle elevated and the part are in operative position.it is now apparent that when the treadle is depressed, the slide-rod 18,acting through the lever 19, immediately starts to slide the driven head2 back against the tension of the spring 6, and as soon as the teeth onthe friction face of the driven head are moved out of mesh with those onthe transmission disks, the nut 22 engages the base 14 and thereafterslides the base and transmission disks along with the driven head 2until the neck of the driven head strikes the shoulder on the shaft 4 atthe end of the squared portion, the parts being so designed that at thispoint the teeth of the transmission disks are out of mesh with those ofthe friction face of the driving head 1. The friction disks are now freeto be an larly adjusted, and the means for accomplishing this adjustmentwill now be described.

It will readily be understood that the speed of rotation imparted to thedriven head depends upon the radial position occupied by the disks 9,since the peripheral speed imparted to these disks depends upon the zoneof contact with the friction face of the driving head 1, being leastwhen this contact zone is nearest the axis of the driving head, as shownin the drawings, and greatest when this contact zone is farthest fromthe axis of the driving head, or substantially 90 from the positionshown in the drawings. Similarly a given peripheral speed of the diskswill transmit the slowest speed of rotation to the driven head when thedisks contact with the outer edge of the friction surface and Willtransmit the fastest speed when they contact with the inner edge of thefriction surface. Between these two extreme positions are severalintermediate positions corresponding with the number of intermediateteeth, since the disks may be moved one tooth at a time, and the teeththus perform the additional function of serving to positively deline theunits of adjustment. To manually operate the bell-crank levers 16 andangularly adjust the transmission disks 9, a roclcshaft 23. runningtransversely of the frame or case 24-, is journaled in bearings 25extending up from the bottom of the ease. and has fixed on its outer endwhich projects through the case 25 a hand lever 26, disposed at theright side of the vehicle in the usual position. The rock-shaft 23 islongitudinally slidable in its bearings and is provided with two keys 2?and 28. the former of which in the position of the shaft shown in Fig. 3engages in a kcywav in an upwardly extending speed-controlling lcvcr2!". This lever 29 has a hub encircling the rockshaft and when engagedby the key 27. it secured to the rock-shaft and oscillated thereby.

The rear ends of the bell-crank levers 1G are secured to a slidableplate 30 through intermediate links 31, and this slidable plate 30 isoperated by the speed-controlling lever 22) through connectionsconsisting of a short link 32, a lever 33 extending obliquely andtransversely across the case 24 and pivoted at its opposite end to avertical pivot 34 journaled in bosses at the top and bottom of the case,and a short backwardly extending link 35 fixed on the upper end of thepivot 34. the link having a slot at its free end into which extends apin 36 on the under side of the plate 30. It is apparent that as theshaft 23 is rocked, the plate 30 will. be caused to slide backward andforward through the connections just described, and the transmissiondisks 9 will be accordingly angularly adjusted. A sector'32 in which thelever 26 is guided and which is attached to the side of the frame 24, isprovided with a number of notches corresponding to the number ofintermediate teeth in the friction faces of the rotary heads 1 and 2,and these notches are engaged by the usual spring-pressed catch and areformed at such intervals that a movement of the spring-pressed catchfrom one notch to another moves the transmission disks one teeth. It ismanifest that the thrust spring 6 tends to hold the parts of thetransmission head in operative contact and also to hold the treadle 17elevated.

At the rear end of the case 24 the driven shaft 4 is split and areversing mechanism interposed which will now be described. Indescribing this mechanism I shall refer to the shaft 4 as the drivingshaft and the continuation of this shaft 4 at the rear of the reversingmechanism as the driven shaft. Fixed on the shaft 4 at its front end isa friction bevel pulley 37 and splined on the adjacent end of the shaft4 is a similar cooperating pulley 38. The pulley 37 carries a tonguedprojection 39 adapted to fit into a grooved projection 40 carried by thecomplementary pulley 38 when the two pulleys are in proximity. In thisposition, therefore. the pulleys are interlocked and rotation istransmitted directly from the driving to the driven shaft. \Vhen thepulley 3 is moved back on the shaft 4 out of interlocking position,direct connection between the two pulleys is eliminated, andintermediate friction pulleys 41 are inserted which serve to reverse thedirection of rotation of the driven shaft 4. To slide the pulley 38 outof interlocking position and at the same time to move the intermediatepulleys 41 into operative position, as shown in Fig. 1. operating meansare provided connected with and operated by the rock-shaft 23. and theseoperating means will now be described.

Two upwardly extending reversing levers 42 and 43,similar in allrespects to the speedcontrolling lever 29 except that they are somewhatshorter, have hubs encircling the rocleshaft 23 and these hubs areprovided with kcyways which areengaged by the keys 27 and 28,respectively, when the shaft 23 is moved longitudinally over toreversing position, as shown in Fig. 1. The sector 32 is provided with atransverse slot at its rear end which connects with a reversing slot onthe inner side of the sector. The lever 26 must, therefore, be pulledback to its extreme rear position in order to enter the transverse slotto slide the rock-shaft 23 over to reversing position, or, in otherwords the vehicle must be on slow speed. before it can be reversed.\Vhen the rockshaft is moved longitudinally over to reversing position,from the position shown in Fig. 3 to that shown in Fig. 1, the key 27 isdisengaged from the speed-controlling lever 29 and engages the reversinglever 42, while, at the same time, the key 28 engages the reversinglever 43 and the reversing levers 42 and 43 are locked to the shaft. Thereversing and SPGQCl-COHtIOlllllg levers bear with their sides betweenvertically extending bearings of the rock-shaft, and springpresseddetents 44 are arranged to snap into sockets in the bottom of the leversto hold them when released by the rock-shaft. so that they will be inproper position for their respective keys to enter their keyways whenthe rock-shaft is moved longitudinally to lock them on the shaft.

The intermediate pulleys 41 are journaled in the upper ends of swingingbearings 45 which are pivoted at their lower ends in bosses or logs onthe bottom of the ease. The upper ends of the swinging bearings 45 arebifurcated and are operativcly connected to the reversing levers 42 and43 through links 46 and 46*, respectively. and vertically pivotedbell-crank levers 47, one end of each of which bell-crank levers isinserted in the bifurcated end of the respective swinging bearings 45.and the other end of each of which is joined to the respective link 46and 46*, which passes through a slotted opening in the arm of itsbell-crank lever and is oined thereto by a nut on one side and a coiledthrust spring anchored in the link on the other side.

Since the intermediate pulleys 41 must be withdrawn before the pulley 38can be moved toward the pulley 37, the link 46 is split and the coiledspring is anchored to one portion of the link and tied over a knob onthe end of the other portion, as shown. so that the spring acts both asa thrust and a compression spring and permits the two levers 47 and 48to move independently.

To slide the pulley 3S backward and forward in conjunction with and atright angles to the movement of the intermediate pulleys 41, anadditional vertically pivoted lever 48 is connected by a pin 4-9 to oneof the two links 46, and the lever 48 has a bifurcated free end whichstraddles over a groove in the neck of the pulley 3S, and slides the 5pulley to and from interlocking position as the lever 18 is swung on itspivot by the link 46. These parts are so designed. that as the shaft isrocked forward the pulley 38 is retracted and the intermediate pulleys41 inserted, and when the shaft is rocked back the pulleys are moved :inthe opposite direction.

To increase the frictional grip of the intermediate pulleys ll with thebevel faces of the pulleys 87 and 38, the engaging faces of all fourpulleys a re provided with similar annular teeth concentric with theaxes of the respective pulleys. These teeth are similar in shape tothose on the friction faces and transmission disks in the transmissionmechanism.

The case 2% is inserted in the frame 50 of the vehicle in convenientposition and is secured to a flange or the frame by bolts passingdownward through outwardly extending lugs on the case, as shown. Asusual the case may be supplied with a. large quantity of lubricant sothat the parts therein will run in oil.

It will be noted that our transmission mechanism performs all theessential functions of a clutch, and therefore the usual clutch may bedispensed with.

It is obvious that various modifications may be made in the constructionshown and above particularly described within the principle and scope ofour invention.

\Ve claim:

I. A power transmission device comprising two friction elements havingoppositely facing friction surfaces, an intermediate friction diskinterposed between the two friction elements in peripheral contact withthe two friction surfaces, the two friction surfaces being provided witha plurality of similar annular teeth arranged concentrically about therespective axes of the friction elements, and the intern'icdiate diskhaving a plurality of circun'iferential teeth adapted to mesh with theteeth of the two friction surfaces, and means for adjusting the angularposition of the intermediate disk.

A power transmission device comprising two friction elements each havingan annular concave friction surface facing that of the complementaryfriction element, the two friction surfaces being provided with aplurality of similar annular teeth arranged concentrically with therespective annular friction surfaces, an intermediate friction diskinterposed between the two friction elements and provided with aplurality of circumferential teeth adapted to mesh with the 65 teeth ofthe two friction surfaces, and means for adjusting the angular positionof the intermediate disk.

3. A power transmission device comprising a driving head having anannular concave friction surface concentric with its axis, a driven headhaving an annular concave friction surface concentric with its axis andfacing that of the driving head, the two friction surfaces beingprovided with a plurality of similar annular teeth arrangedconcentrically with the respective friction surfaces, a transmissiondisk having a plurality of circumferential teeth adapted to mesh withthe teeth of the two friction surfaces, the transmission disk beingdisposed between the two heads with its teeth meshing with those of bothfriction surfaces, and means for adjusting the angular position of thetransmission disk to vary the speed of rotation imparted to the drivenhead.

4. A power transmission device comprising a driving head having anannular concave friction surface concentric with its axis, a driven headhaving an annular concave friction surface concentric with its axis andfacing that of the driving head, the two friction surfaces beingprovided with a plurality of similar annular teeth arrangedconcentrically with the respective friction surfaces, a transmissiondisk having a plurality of circumferential teeth adapted to mesh withthe teeth of the two friction sur faces, the transmission disk beingdisposed between the two heads with its teeth meshing with those of bothfriction surfaces, means for engaging and disengaging the three membersby movement toward and from each other, and means for adjusting theangular position of the transmission disk to vary the speed of rotationimparted to the driven head.

5. A power transmission device con1prising a driving shaft and a drivinghead fixed thereon having an annular concave friction surface concentricwith its axis, a driven shaft and a driven head slidably mounted thereonhaving an annular concave friction surface concentric with its axis andfacing that of the driving head, the two friction surfaces beingprovided with a plurality of similar annular teeth arrangedconcentrically with the respective friction surfaces, two transmissiondisks each having a plurality of circninferential teeth adapted to meshwith the teeth of the two friction surfaces, the transmission disksbeing disposed on opposite sides of the driving shaft between the twoheads and meshing with the teeth of the friction, surfaces atcorresponding radii, resilient means operative to normally hold thedriven head in engagement with the transmission disks, means arranged tomove the driven head out of engagement with the transmission disks andto move the transmission disks out of engagement with the driving head,and manually operative means to similarly adjust the annular dispositionof the two transmission disks.

6. A power transmission device comprising a driving shaft and a drivinghead fixed thereon having an annular concave friction surface concentricwith its axis, a driven shaft and a driven head slidably mounted thereonhaving an annular concave friction surface concentric with its axis andfacing that of the driving head, the two friction surfaces beingprovided with a pin ality of similar teeth arranged concentrically withthe respective friction surfaces, two transmission disks each having aplurality of circumferential teeth adapted to mesh with the teeth on thetwo friction surfaces, the transmission disks being disposed on oppositesides of the driving shaft between the two heads and meshing with theteeth of the friction surfaces at corresponding radii, a support for thetransmission disks slidable toward and from the driving head, resilientmeans tending to hold the two heads and the transmission disks inoperative engagement, means for successively moving the driven head outof engagement with the transmission disks and moving the support for thetransmission disks to disengage the disks from the driving head, andmanually operative means to similarly adjust the radial disposition ofthe two transmission disks.

7. A power transmission device comprising a driving shaft and a drivinghead fixed thereon having an annular concave friction surface concentricwith its axis, a driven shaft and a driven head slidably mounted thereonhaving an annular concave friction surface concentric with its axis andfacing that of the driving head, the two friction surfaces beingprovided with a plurality of similar annular teeth arrangedconcentrically with the respective friction surfaces, two transmissiondisks each having a plurality of circumferential teeth adapted to meshwith the teeth on the two friction surfaces, the transmission disksbeing disposed on opposite sides of the driving shaft between the twoheads and meshing with the teeth of the friction surfaces atcorrespondin radii, a support for the transmission disks slidable towardand from the driving head, resilient means tending to hold the two headsand the transmission disks in operative engagement, means forsuccessively moving the driven head out of engagement with thetransmission disks and moving the support for the transmission disks todisen gage the disks from the driving head, a manually operativerock-shaft, and connecting means between the rock-shaft and thetransmission disks arranged to adjust the radial disposition of thetransmision disks as the shaft is rocked.

8. A friction transmission device comprising a rotary driving head, andan oppositely disposed rotary driven head movable toward and away fromthe driving head, a friction transmission disk peripherally engagingboth driving heads, a slidable carrier for the transmission disk, andmanually operative means for successively moving the driven head awayfrom the transmission disk and the transmission disk away from thedriving head.

9. A friction transmission device comprising a rotary driving head andan oppositely disposed rotary driven head movable toward and away fromthe driving head, a friction transmission disk peripherally engagingboth driving heads, a slidalole carrier for the transmission disk,resilient means tending to hold the three members in contact, andmanually operative means for successively moving the driven head awayfrom the transmission disk and the transmission disk away from thedriving head.

10. A friction transmission device comprising a rotary driving headhaving an annular concave friction surface, an oppositely disposeddriving head movable toward and away from the driving head and having afriction surface similar to and registering with that of the drivinghead, the two friction surfaces being provided with a plurality ofannular teeth arranged concentrically with the respective frictionsurfaces, a friction transmission disk provided with circumferentialteeth adapted to mesh with the teeth of the two friction surfaces, thetransmission. disk being disposed between the two heads with its teethmeshing with those of the two friction surfaces, a slidahle carrier forthe transmission disk, resilient means tending to hold the three membersin contact, and manually operative means for successively moving thedriven head away from the transmission disk and the transmission diskaway from the driving head.

11. A friction transmission device comprising a rotary driving headhaving an annular concave friction surface, an oppositely disposeddriving head movable to ward and away from the driving head and having afriction surface similar to and registering with that of the drivinghead, the two friction surfaces being provided with a plurality ofannular teeth arranged concentrically with the respective frictionsurfaces, a plurality of friction transmission disks provided withcircumferential teeth adapted to mesh with the teeth of the two frictionsurfaces, the two transmission disks being disposed at correspondingradii between the two heads with their teeth meshing with those of thetwo friction surfaces, a slidable carrier for the transmission disks,resilient means tending to hold the three members in contact, manuallyoperative means for successively moving the driven head away from thetransmission disks and the transmission disks away from the drivinghead, and manually operative means for similarly adjusting the radialdisposition of the transmission disks.

12. A friction transmission mechanism comprising a pair of oppositelydisposed rotary heads each having a friction surface, one of the headsbeing slidably mounted for movement toward and away from itscomplementary head, a rotary friction transmission disk disposed infrictional engagement with the two friction surfaces and held againstbodily circular movement about the axes of the rotary heads, means forsuccessively moving the slidable head out of engagement with thetransn'iission disk and the transmission disk out of engagement with thestationary head, and means for adjusting the angular disposition of thetransmission disk to vary the speed of r0tation transmitted thereby.

13. A friction transmission mechanism comprising a pair of oppositelydisposed rotary heads each having a friction surface, one of the headsbeing slidably mounted for movement toward and away from itscomplementary head, a rotary friction transmission disk disposed infrictional engagement with the two friction surfaces and held againstbodily circular movement about the of the rotary heads. resilient meansnormally holding the slidable head with its friction surface inengagement with the transmission disk, manually operative means forsuccessively moving the slidable head against the tension of theresilient means away from the transmission disk and the transmissiondisk out of engagement with the stationary head, and means for adjustingthe angular disposition of the transmission disk to vary the speed ofrotation transmitted thereby.

14. A friction transmission mechanism comprising a pair of oppositelydisposed rotary elements each having an annular concave friction surfaceprovided with annu lar teeth, one of the heads being slid-ably mounted,a rotary friction transmission disk having circumferential teeth anddisposed with its teeth meshing in those of the friction surfaces, acarrier for the transmission disk mounted for sliding movement and heldagainst bodily circular movement about the axes of the rotary elements,resilient means normally holding the two heads and transmission wheel inengagement, manually operative-means for successively moving theslidable head away from the transmission disk and the transmission diskaway from the non-slidable head, thereby separating the three elements,and means for adjusting the angular disposition of the transmission diskto vary the speed of rotation trans mitted thereby.

15. A power transmission device comprising a pair of oppositely disposedrotary heads each having a friction surface, a transmission diskdisposed in frictional engagement with the two friction surfaces andarranged to transmit rotation from one rotary head to the other; areversing mechanism comprising a driving and a driven friction pulleyarranged to interlock and rotate together in the same direction when inproximity to each other, one of the pulleys being slidablc toward andaway from its complementary pulley, and an intermediate friction pulleyarranged to engage with the two pulleys and reverse the direction ofrotation of the driven pulley; a rock shaft, and means connecting therock shaft with the transmission disk, the intermediate pulley and theslidable pulley to adjust the radial disposition of the transmissiondisk between the two friction surfaces and to move the slidable pulleyinto and out of interlocking engagement with its complementary pulleyand to move the intern'icdiate pulley into and out of reversing positionas the shaft is rocked.

16. A power transmission device comprising a pair of oppositely disposedrotary heads each having a friction surface, a transmission diskdisposed in frictional engagement with the two friction surfaces andarranged to transmit rotation from one rotary head to the other; areversing mechanism comprising a driving and a driven friction pulleyarranged to interlock and rotate. together in the same direction when inproximity to each other, one of the pulleys being slidable toward andaway from its complementary pulley, and an intermediate friction pulleyarranged to engage with the two pulleys and reverse the direction ofrotation of the driven pulley, the pulleys being provided with annularconcentric teeth arranged so that the teeth on the intermediate pulleymesh with those on the other two pulleys in reversing position andincrease the frictional grip; a rock shaft, and means connecting therock shaft with the transmis sion disk, the intermediate pulley and theslidable pulley to adjust the radial disposition of the transmissiondisk between the two friction surfaces and to move the slidablc pulleyinto and out of interlocking engagement with its complen'lentary pulleyand to move the intermediate pulley into and out of reversing positionas the shaft is rocked.

17. A power transmission device comprising a pair of oppositely disposedrotary heads each having a friction surface, a transmission diskdisposed in frictional engagement with the two friction surfaces andarranged to transmit rotation from one 1'0- tary head to the other; areversing mecha nism comprising a driving and a driven friction pulleyarranged to interlock and rotate together in the same direction when inpr0ximity to each other, one of the pulleys being slidahle toward andaway from its complementary pulley, and an intermediate frie tion pulleyarranged to engage with the two pulleys and reverse the direction ofrotation of the driven pulley; a longitudinally slidable rock shaft.means arranged to connect the transmissiondisk with the rock shaft whenthe rock shaft is in one position of longitudinal adjustment and toadjust the radial. disposition of the transmission disk between the twofriction surfaces as the shaft is rocked, and means arranged to connectthe intermediate pulley and the slidable pulley with the rock shaft whenthe rock shaft is in another position of longitudinal adjustment and tosuccessively move the slidable pulley out of interlocking connec tionwith its complementary pulley and to move the intermediate pulley intoreversing position as the shaft is rocked in one direction and toreverse the movement of the slidable and intermediate pulleys as theshaft is rocked in the opposite direction.

18. A power transmission device comprising a pair of oppositely disposedrotary heads each having a friction surface, a transmission diskdisposed in friction engagement with the two friction surfaces andarranged to transmit rotation from one rotary head to the other; areversing mechanism comprising a driving and a driven friction pulleyarranged to interlock and rotate together in the same direction when inproximity to each other, one of the pulleys being slidable toward andaway from its complementary pulley, and an intermediate friction pulleyarranged to engage with the two pulleys and reverse the direction ofrotation of the driven pulley, the pulleys being provided with annularconcentric teeth arranged so that the teeth on the intermediate pulleymesh with those on the other two pulleys in reversing position andincrease the frictional grip, a longitudinally slidable rock shaft,means arranged to connect the transmission disk with the rock shaft whenthe rock shaft is in one position of longitudinaladjustment and toadjust the radial disposition of the transmission disk between the twofriction surfaces as the shaft is rocked, and means arranged to connectthe intermediate pulley and the slidable pulley with the rock shaft whenthe rock shaft is in another position of longitudinal adjust ment and tosuccessively move the slidable pulley out of interlocking connectionwith its complementary pulley and to more the intermediate pulley intoreversing position as the shaft is rocked in one direction and toreverse the movement of the slidable and intermediate pulleys as theshaft is rocked in the opposite direction.

In testimony whereof we have affixed our signatures in presence of twowitnesses.

HERBERT E. MARSHALL. ROBERT ISAKSEU. itnesses Vic'mn D. Bons'r, BERNARDCownN.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents. Washington, D. 0.

